Wireless Remote Control wireless remote control
Today, wireless remote control has in life are more and more applied, brings people great convenience. With the progress of science and technology of wireless remote controller has expanded into many types, simply have 2 kinds commonly, one is used in the household appliances remote control pattern ( IR Remote Control ), the other is a burglar alarm equipment, remote control, remote control car doors and windows and so on common radio remote control model ( RF Remote Control ). Each of them has different advantages,electric appliance
application fields are also differentiated.
Who invented the first remote controller has not test. But the earliest one of the remote controller, is called a Nicola Tesla ( Nikola Tesla ) ( 1856-1943 ) inventor in 1898 developed ( USA Patent No. 613809), called" Method of and Apparatus for Controlling Mechanism of Moving Vehicle or Vehicles."
Wireless remote control type
Infrared remote controller
Infrared remote control ( IR Remote Control ) is the use of a wavelength of 0.76 1.5 ~ m between near infrared light to transmit a control signal to the remote control device.
Common infrared remote control system in general is divided two parts: sender and receiver.
The transmitter portion of main components for the infrared light emitting diode. It is actually a special light emitting diode,control class
due to its internal material differs from the ordinary light-emitting diode, which at its ends to exert a certain voltage, it emits infrared rather than visible light.
The current extensive use infrared light-emitting diodes to emit an infrared wavelength is about 940nm, the same general shape and light emitting diode, but different colours.
The receiving portion of the main components for the infrared receiving diode, generally has two kinds of circular and square. In practical application to the infrared receiving diode reverse bias, for it to work properly, or infrared receiving diode on the circuit in the application of reverse use, so as to obtain high sensitivity.
Due to the infrared LED transmitter power is generally small ( about 100mW), so the infrared receiving diode receives the signal is very weak, so we should increase the high gain amplifier circuit, in recent years mostly adopts finished infrared receiver head.
The finished product by the infrared receiving head package roughly two ways: using a metal shield; a plastic package. Both three pin, whereby the power supply is (VDD ), the power of negative (GND ) and data output ( VOUT ). The infrared receiving head pin arrangement for different models and different, can refer to the manufacturer's instructions. The finished product by the infrared receiving head has the advantages of no need of complex debugging and shielding shell, is used as a three transistor, a very convenient. But the attention in the use of the finished product by the infrared receiving head carrier frequency.
Infrared remote control of the carrier frequency is 38kHz, which is composed of a transmitting terminal used by the 455kHz crystal to decide.power transistor At the transmitting end to the oscillator for integer frequency divider, frequency dividing coefficients generally take 12 / 12 = 37.9, 455kHz kHz = 38kHz. There are also some remote control system using 36kHz, 40kHz, 56kHz, generally by the transmitting end of crystal oscillation frequency to decide.
Infrared remote control feature does not affect the surrounding environment, do not interfere with other electrical equipment. Due to its inability to penetrate walls, so different rooms can use a common household remote controller without mutual interference; circuit debugging is simple, as long as the given circuit connection without error, without debugging can be put to work; codec easily, can carry out remote control. Therefore, now the infrared remote control in household appliances, indoor distance ( less than 10 meters ) remote control has been widely used.